1. Technical Field
The present invention relates to a front assembly in a heavy goods vehicle, which front assembly interacts with a front portion of a longitudinal frame included in the vehicle and in which there is included a means for providing underrun protection, which means in turn comprises (includes, but is not limited to) a rigid force-absorbing beam structure. The invention also relates to a method for providing and/or assembling such a beam structure.
2. Background
Heavy goods vehicles, primarily cargo vehicles, have long been equipped with underrun protection for the purpose of preventing a smaller and lower vehicle from being partially pushed in under the heavy goods vehicle in the event of a collision. In the event of a front collision between a car and a cargo vehicle that does not have underrun protection, the passenger compartment and front part of the car generally end up under the cargo vehicle due to the large difference in height between the bumpers of the car and the heavy vehicle. Also, considerably higher collision forces are exerted on the passenger compartment of the car than is the case when the cargo vehicle is equipped with underrun protection. When so equipped, the underrun protection causes the energy to instead be primarily absorbed in the front portion of the car and in this way the collision force against the passenger compartment can be considerably reduced.
Front underrun protection, as the name implies, is typically arranged in the front of the vehicle immediately inside or behind a traditional bumper. The underrun protection is usually constituted by a separate, force-absorbing and rigid beam structure, which by means of supporting consoles, is arranged in the vehicle.
Conventionally, the underrun protection has been made energy-absorbing in various ways by construction-wise controlling the deformation of a beam structure, and its supporting consoles, in such a way that the deformation of the underrun protection, in the event of a collision, absorbs energy together with a deformation zone of the colliding smaller vehicle to reduce the collision force against the passenger compartment in the smaller vehicle.
A problem with previously known underrun protection systems and methods is, however, that they are relatively time consuming to assemble on the vehicle due to, for example, reasons of handling since the beam structure is relatively heavy and difficult to position when attaching it to the vehicle. Another problem with heavier vehicles is that more and more adjustment work and more adjustable consoles are necessary to satisfy the increasing demands for an aesthetically appealing front; that is to say, adjustments must be made so that spaces and play between the components will be kept within small tolerances, preferably on a level with the finish of a car. This problem becomes especially emphasized in those cases when large units with many components, also referred to as so-called modules, are produced within manufacturing units especially intended for this purpose, either separately, but internal to the vehicle producer, or externally at an outside producer, and then brought to the assembly line where they are assembled on the vehicle, and are then to fit together as a whole.